YOVOBS Exhaust Manifold Gasket Kit 12617944 MLS — 2 Gaskets & 12 Stainless Bolts, High-Temp Direct-Fit for LS Engines

YOVOBS 12617944 is a high-temperature multi-layer steel (MLS) exhaust manifold gasket and hardware kit engineered to replace OE part numbers for most LS-family V8 engines, delivering a reliable seal and corrosion-resistant bolts for long-lasting exhaust integrity.

This complete kit is built to match original equipment specifications and includes two MLS header gaskets plus twelve stainless steel flange bolts. It’s designed for direct-fit installation on a wide range of GM LS-series engines (excluding LS7) so you can restore proper exhaust sealing, reduce noise and vibration, and avoid the fitment headaches that come with mismatched parts. All components are produced with durability and high-heat performance in mind, making the set suitable for everyday drivers and performance builds alike.

Which engines and vehicles will this kit fit?

The YOVOBS 12617944 kit fits most LS-series GM V8 engines (except LS7) and the corresponding models that use the listed OE part numbers. Compatibility spans popular displacements and model families, making it a flexible replacement for many trucks, SUVs, muscle cars, and performance builds.

• Compatible LS engines: LS1, LS2, LS3, LS6, LM7, LR4, LQ4, L59, LQ9, LM4, L33, etc.
• Typical displacements: 4.8L, 5.3L, 5.7L, 6.0L, 6.2L V8
• Vehicle applications: Chevy, GMC, Cadillac, Buick, Pontiac, Hummer, Isuzu, Saab models like Silverado, Sierra, Camaro, Corvette, Tahoe, CTS, Escalade and more
• OE part cross-reference: 12617944, 12558573, 12600530, 12620947, MS16124; Bolt OE#551696

How does the MLS gasket handle high temperatures and pressure?

The multi-layer steel (MLS) construction provides a tight, resilient seal that resists warping and blowouts under repeated thermal cycles. MLS gaskets maintain clamping force and resist exhaust gas leakage better than single-layer or composite options, which helps keep engine noise and emissions where they belong.

• High-density steel layers for thermal stability
• Designed to resist pressure differentials and gasket creep
• Maintains seal through repeated heating and cooling cycles
• Reduces exhaust leaks that cause noise and vibration

What’s included and why are the bolts upgraded?

The kit supplies two exhaust manifold header gaskets plus twelve stainless-steel flange bolts sized M8 x 1.25 with a 25mm underhead length. These bolts have integrated washers to ensure even clamping load and improved resistance to rust compared with standard OEM hardware.

• 2 x MLS exhaust manifold/header gaskets — direct-fit replacements
• 12 x stainless steel flange bolts with built-in washers for uniform clamping
• Bolts sized M8 x 1.25, 25mm underhead length — anti-corrosion finish
• Hardware selected for durability in harsh engine-bay environments

How easy is installation and what should I check before buying?

Installation is straightforward for anyone familiar with exhaust manifold work: remove the old gasket, clean mating surfaces, and torque the new bolts to specification. Always confirm vehicle fitment against the OE numbers and inspect the manifold surface for warpage before installing the new gasket.

• Direct-fit design minimizes modification or rework
• Clean and flat mating surfaces required for proper sealing
• Check OE part numbers and engine model for compatibility
• Use correct torque sequence to prevent leaks and gasket failure

Who is this for: The YOVOBS 12617944 MLS gasket and 12-bolt kit is intended for mechanics, DIY enthusiasts, and performance builders who need a dependable, OE-matching exhaust manifold seal for LS-series engines. It’s a practical choice for restoring factory-level sealing on older vehicles, upgrading hardware for corrosion resistance, or completing a high-performance exhaust installation where heat resistance and long-term reliability matter.